1. Field of the Invention
The present invention relates to substance and material identifying, including detection, inspection, and classification. More particularly, the present invention relates to a method and system operating in the x-ray portion of the electromagnetic spectrum to identify specific elements and unique mixtures of elements that are components in controlled substances.
2. Discussion of the Related Art
Detection of explosives and controlled substances is increasing in importance. Whether at the airport, a building, or in military applications, quick and confident detection is needed for safety and convenience. Detection techniques are preferable to random searches that require one to make their selves and bags available for visual searches. Plus, detection techniques may be employed for a higher confidence level that everyone or everything has been subjected. Current detection techniques may include neutron activation analysis, x-ray absorption and scattering, resonance fluorescence directly on nuclei in the substance, quadrupole resonance with the nucleus of atoms, and various chemical sensors.
Neutron activation may require a large energy source, such as an accelerator, that consumer high power to be capable of measuring the ratios of atomic constituents directly, such as hydrogen, oxygen, nitrogen, and carbon. X-ray absorption and scattering may require complex predictive software, which may result in a high false alarm rate. Resonance fluorescence may require a large, complex energy source for operation. Quadrupole resonance techniques may suffer from a short range of reliable detection. Chemical sensors may have a slow response and a short range, and may not operate reliably under certain environmental conditions, such as high humidity.